Sketch not able to extrude

hervé_pipon

Hello,
I created a features which create a spline.
Most of the times I can extrude the spline, but sometimes it is not possible and I don't know why.
For me the spline is closed !
Do you have any idea ?

1/ With  problem
The left one is done manually , the right one is created through the feature.




2/ Without problem 
The left one is done manually , the right one is created through the feature.

S1mon

How are you creating your spline? Can you share the document or at least some examples of working and failing splines?

hervé_pipon

https://cad.onshape.com/documents/2bf8b7839963a2ca25fc2ed3/w/01f06eec6e24c28ed1db24bd/e/d2c3ca423723ef9885c734d8?renderMode=0&uiState=64ce6be960715a071e42502d

S1mon

The problem is that your spline is self-intersecting. 

Here's a zoom in of the area:



If you pick enough of the faces it will extrude:

Keep in mind that Parasolid can't deal with solids which join at an edge or point. 

hervé_pipon

Well done and thank you

I had not seen this defect, I checked it exists from the origin of the creation of this form.

On the other hand I am very curious to know how you managed to find this problem, it seems really difficult to me..

S1mon

hervé_pipon said:

Well done and thank you

I had not seen this defect, I checked it exists from the origin of the creation of this form.

On the other hand I am very curious to know how you managed to find this problem, it seems really difficult to me..

Too many points on splines are often problematic. I could see a lot bunched up, so I zoomed in, and then when I saw a tangled mess, I knew there was an issue. 

In general you want to use as few points as possible.